Speaker
Zhiwei Xia
(Southwestern Institute of Physics)
Description
The function of Gas Injection System[1][1] (GIS), in ITER machine, is to deliver the fuelling and impurity gases into the torus. As an important sub-system of GIS, Fusion Power Shut-down System (FPSS) provides the function of emergency shut down for torus safety. The assessment of magnetic field in Tokamak building shows that a high stray field will exist in port cells during burning plasma operation and its maximum value at FPSS box location can reach 0.205 T in ‘Full Operation Scenario 17MA’ case [2] [2]. Thus, shielding for magnetic sensitive component inside FPSS box becomes an important issue to be solved in FPSS design phase.
Inside the FPSS box, only the SV, used to actuate the pneumatic isolation valve, is susceptible to magnetic field. Experiments show that the maximum allowable magnetic field for the SV is 0.013 T considering a margin of 3 dB[3][3]. Therefore, the objective of the shielding design is to ensure the residual field lower than 0.013 T within the shield space.
A soft iron local shield is considered from engineering design viewpoint since only one SV needs to be shielded from stray magnetic field. Half open structure with inner dimension of 120mm×115mm×60mm and 30mm thickness is designed to keep the accessibility and maintainability of the SV. This shield is deployed in the same plane with four pressure switches, and the layout is carefully designed to avoid the magnetic interference as much as possible. The magnetostatic analysis by ANSYS APDL software package indicates that the maximum residual field will be lower than 0.003 T under any direction of poloidal field of 0.205 T. At least 50% design margin is left and more details will be present in the paper later.
Co-authors
Bo Li
(Southwestern Institute of Physics, Chengdu, China)
Maruyama So
(ITER Organization, Route de Vinon sur verdon, 13115 Saint Paul Lez Durance, France)
Wei Li
(Southwestern Institute of Physics, Chengdu, China)
Yu Yang
(ITER Organization, Route de Vinon sur verdon, 13115 Saint Paul Lez Durance, France)
Zhiwei Xia
(Southwestern Institute of Physics, Chengdu, China)
